Evaluating Economic Losses Caused by Pathogens of Fruit and Nut Crops. C. R. Heaton, Graduate Student, Department of Plant Pathology, University of California, Davis 95616. J. M. Ogawa, Professor, and G. Nyland, Professor, Department of Plant Pathology, University of California, Davis 95616. Plant Dis. 65:886-888. Accepted for publication 18 February 1981. Copyright 1981 American Phytopathological Society. DOI: 10.1094/PD-65-886.

Optimal decisions on crop management, fungicide regulations, and research priorities cannot be made without reliable estimates of economic losses caused by plant pathogens. The major obstacle preventing a more accurate assessment of these losses is lack of information about the biological effects of the pathogens on crops. Several approaches can be used to calculate the economic losses of an individual producer of fruit and nut crops. In many cases, the best estimate of economic losses caused by pathogens of fruit and nut crops is a measure of the reduction in the grower's net profits discounted over the remaining life of the orchard. This approach is used to calculate approximate losses from Prunus ringspot virus in a newly planted peach orchard.